> -----Original Message----- > From: Thomas Girard [mailto:[EMAIL PROTECTED] > Sent: Saturday, September 23, 2006 11:04 AM > To: Harling, Torsten > Cc: [EMAIL PROTECTED] > Subject: Re: Bug#380739: boost compiles differently, if ACE > header is included first > > Hello Torsten, > > On Mon, Aug 07, 2006 at 07:08:39PM +0200, Thomas Girard wrote: > > > > Another way of enforcing correct flags would be to > check whether > > > > symbol _REENTRANT is defined, and if it is not, the > header could > > > > abort compilation with an #error stating _REENTRANT > *must* be defined. > > > > > > > > I am not convinced this is better. What do you think? > > > > > > We first used shared_ptr's about 3 or 4 years ago. That's > when this > > > bug hid itself undetected in our software. We only wondered, why > > > using a shared_ptr would sometimes cause our software to hang. > > > > > > The cause was, that mostly the shared_ptr ended up having > no mutex. > > > But, if a piece of code included the ace headers first, it might > > > hang when using a shared_ptr, that was constructed in a different > > > compilation unit. > > > > > > An #error stating _REENTRANT *must* be defined, or even better, > > > saying -pthread(s) *must* be used, would have prevented and fixed > > > our bug a long time ago. I agree, that the latter would be more > > > difficult, as you would have to figure out the correct option for > > > different compilers and architectures. > > > > > > So, I would recommend the #error. > > > > > > The boost library also #error's out, if it requires > multithreading > > > support. > > I have a fix for this bug, and it seems to work. > > But using boost 1.33.1-7 (from unstable) on your example no > longer works (with or without my patch). Indeed now boost > #define _REENTRANT, because <memory> gets included to use > libstdc++ allocator. If you believe that's a problem, please > file a bug on boost. > > I am disabling the patch because with it, we would have another > problem: including a boost header first works, but including > an ACE header first would error out. > > The patch is attached to this email. > > What is your opinion on this? >
Hi, thanks for the patch. It will work for us. I don't know, if the -pthread option of gcc does anything besides defining _REENTRANT (and adding -lpthread to ld). If it does, that might also cause trouble, but that would not be an ACE problem. BTW: Boost 1.33 does not need a pthread_mutex for a shared_ptr. Instead that version uses atomic operations to change the counters, so that my initial problem would have vanished automatically, if we used a newer boost version. Thanks, Torsten
